The invention relates to a method of making a solid fertilizer by separation of liquid manure into a solid and a liquid phase by means of a filter vessel into which the liquid manure is charged and left therein in a resting stage until a solid layer is separated on the top and a liquid phase therebelow, and thereafter the liquid phase is discharged by opening at least one closeable discharge opening (in accordance with the German patent application No. P 29 43 962.1-23).
This method in accordance with the above patent application is characterized with respect to comparable methods, in particular that in a time and cost saving manner the liquid phase is separated from the solid phase of the liquid manure by a modified discharging of the liquid phase in a time controllable filter process, whereby basically no complicated structure not operating costs involving excessive oil, gas or electricity consumption are required.